Pipelines, sewer or drainage channel with a diameter ranging from 0.80 meters to the cross-sectional area of 0.50 square meters and a support structure. Or length of 100 m.
Water pipe, sewer or sluice with a diameter of from 0. 80 meters above หรือ area from 0. 50 square meters up and support structure. Or have long since 100 meters above.